/* StackNest site: one stylesheet for both languages. Dark and light share the layout; only the tokens differ. */

:root {
  --bg: #111113;
  --bg-band: #18181B;
  --surface: #1B1B1E;
  --surface-border: transparent;
  --text: #EDEDE8;
  --text-muted: #B4B4AE;
  --text-faint: #8E8E89;
  --nav-text: #C9C9C4;
  --line: #3A3A3F;
  --rule: #26262A;
  --accent: #F5C842;
  --accent-text: #F5C842;
  --accent-ink: #111113;
  --code-bg: #1B1B1E;
  --code-text: #D8D8D2;
  --phone-border: transparent;
  --toggle-bg: #1B1B1E;
  --focus: #F5C842;
  color-scheme: dark;
}

:root[data-theme="light"] {
  --bg: #F7F7F5;
  --bg-band: #EEEEEA;
  --surface: #FFFFFF;
  --surface-border: #E6E6E1;
  --text: #17171A;
  --text-muted: #55555A;
  --text-faint: #6A6A6E;
  --nav-text: #45454A;
  --line: #D6D6D1;
  --rule: #E2E2DC;
  --accent: #F5C842;
  --accent-text: #8A6100;
  --accent-ink: #17171A;
  --code-bg: #17171A;
  --code-text: #E6E6E1;
  --phone-border: #DCDCD6;
  --toggle-bg: #FFFFFF;
  --focus: #17171A;
  color-scheme: light;
}

/* Without the script (or before it runs) follow the system appearance. */
@media (prefers-color-scheme: light) {
  :root:not([data-theme]) {
    --bg: #F7F7F5;
    --bg-band: #EEEEEA;
    --surface: #FFFFFF;
    --surface-border: #E6E6E1;
    --text: #17171A;
    --text-muted: #55555A;
    --text-faint: #6A6A6E;
    --nav-text: #45454A;
    --line: #D6D6D1;
    --rule: #E2E2DC;
    --accent-text: #8A6100;
    --accent-ink: #17171A;
    --code-bg: #17171A;
    --code-text: #E6E6E1;
    --phone-border: #DCDCD6;
    --toggle-bg: #FFFFFF;
    --focus: #17171A;
    color-scheme: light;
  }
}

*, *::before, *::after { box-sizing: border-box; }

html { scroll-behavior: smooth; }
@media (prefers-reduced-motion: reduce) { html { scroll-behavior: auto; } }

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: "Zen Kaku Gothic New", "Hiragino Sans", "Hiragino Kaku Gothic ProN", system-ui, sans-serif;
  line-height: 1.7;
  -webkit-text-size-adjust: 100%;
}

a { color: var(--accent-text); }
a:hover { text-decoration: underline; }
img { display: block; max-width: 100%; height: auto; }
code, pre { font-family: "JetBrains Mono", ui-monospace, Menlo, monospace; }

.wrap { max-width: 1200px; margin: 0 auto; padding-left: 24px; padding-right: 24px; }

.skip { position: absolute; left: -9999px; top: 8px; }
.skip:focus { left: 16px; z-index: 10; background: var(--surface); color: var(--text); padding: 8px 12px; border-radius: 8px; }

/* Header */
.site-header .wrap { display: flex; flex-wrap: wrap; align-items: center; justify-content: space-between; gap: 16px; padding-top: 24px; padding-bottom: 24px; }
.brand { display: flex; align-items: center; gap: 12px; color: var(--text); text-decoration: none; }
.brand:hover { text-decoration: none; }
.brand span { font-weight: 900; font-size: 22px; letter-spacing: 0.02em; }
.brand .book-a { stroke: var(--accent); }
.brand .book { stroke: var(--text); }
.site-nav { display: flex; flex-wrap: wrap; align-items: center; gap: 12px 28px; font-size: 15px; }
.site-nav > a { color: var(--nav-text); text-decoration: none; }
.site-nav > a:hover { color: var(--text); }
.lang { display: flex; gap: 4px; border: 1px solid var(--line); border-radius: 999px; padding: 4px; }
.lang a { padding: 4px 12px; border-radius: 999px; color: var(--nav-text); text-decoration: none; font-size: 13px; }
.lang a[aria-current="page"] { background: var(--text); color: var(--bg); }
.theme-toggle {
  display: inline-flex; align-items: center; justify-content: center;
  width: 44px; height: 44px; border-radius: 999px;
  border: 1px solid var(--line); background: var(--toggle-bg); color: var(--text); cursor: pointer;
}
.theme-toggle:focus-visible, a:focus-visible { outline: 2px solid var(--focus); outline-offset: 2px; }
.download a:focus-visible { outline-color: #111113; }
.theme-toggle .icon-moon { display: none; }
:root[data-theme="light"] .theme-toggle .icon-sun { display: none; }
:root[data-theme="light"] .theme-toggle .icon-moon { display: block; }
@media (prefers-color-scheme: light) {
  :root:not([data-theme]) .theme-toggle .icon-sun { display: none; }
  :root:not([data-theme]) .theme-toggle .icon-moon { display: block; }
}

/* Screenshots that differ by appearance */
.for-light { display: none; }
:root[data-theme="light"] .for-dark { display: none; }
:root[data-theme="light"] .for-light { display: block; }
@media (prefers-color-scheme: light) {
  :root:not([data-theme]) .for-dark { display: none; }
  :root:not([data-theme]) .for-light { display: block; }
}

/* Hero */
.hero { display: flex; flex-direction: column; align-items: center; text-align: center; gap: 24px; padding-top: 72px; padding-bottom: 40px; }
.eyebrow { margin: 0; font-size: 14px; letter-spacing: 0.12em; text-transform: uppercase; color: var(--accent-text); font-weight: 700; }
.hero h1 { margin: 0; font-size: clamp(38px, 6vw, 76px); line-height: 1.15; font-weight: 900; letter-spacing: -0.01em; }
.hero .lead { margin: 0; max-width: 720px; font-size: 18px; color: var(--text-muted); }
.actions { display: flex; flex-wrap: wrap; justify-content: center; gap: 12px; margin-top: 8px; }
.btn { display: inline-flex; align-items: center; gap: 10px; padding: 14px 26px; border-radius: 12px; text-decoration: none; font-size: 16px; min-height: 44px; }
.btn:hover { text-decoration: none; }
.btn-primary { background: var(--accent); color: var(--accent-ink); font-weight: 700; }
.btn-primary:hover { filter: brightness(1.05); }
.btn-secondary { border: 1px solid var(--line); color: var(--text); background: transparent; }
:root[data-theme="light"] .btn-secondary { background: #FFFFFF; }
@media (prefers-color-scheme: light) { :root:not([data-theme]) .btn-secondary { background: #FFFFFF; } }
.meta { margin: 0; font-size: 13px; color: var(--text-faint); }

.shot-hero { max-width: 1240px; padding-bottom: 96px; }

/* Sections */
section { scroll-margin-top: 16px; }
.section { padding-bottom: 112px; }
.section h2 { margin: 0; font-size: clamp(28px, 3.4vw, 40px); font-weight: 900; line-height: 1.3; }
.section-head { display: flex; flex-wrap: wrap; align-items: flex-end; justify-content: space-between; gap: 16px; margin-bottom: 32px; }
.section-head p { margin: 0; max-width: 520px; color: var(--text-muted); font-size: 15px; }

.pillars h2 { margin-bottom: 40px; }
.cards { display: grid; grid-template-columns: repeat(auto-fit, minmax(280px, 1fr)); gap: 24px; }
.card { background: var(--surface); border: 1px solid var(--surface-border); border-radius: 20px; padding: 32px; display: flex; flex-direction: column; gap: 12px; }
.card .num { font-family: "JetBrains Mono", ui-monospace, monospace; color: var(--accent-text); font-size: 14px; }
.card h3 { margin: 0; font-size: 22px; font-weight: 700; line-height: 1.4; }
.card p { margin: 0; color: var(--text-muted); font-size: 15px; }

.pair { display: grid; grid-template-columns: repeat(auto-fit, minmax(320px, 1fr)); gap: 24px; }

.band { background: var(--bg-band); padding: 96px 0; margin-bottom: 112px; }
.band .wrap { display: flex; flex-wrap: wrap; align-items: center; gap: 56px; }
.band-text { flex: 1 1 360px; display: flex; flex-direction: column; gap: 16px; }
.band-text p { margin: 0; color: var(--text-muted); font-size: 16px; }
.band-text h2 { margin: 0; font-size: clamp(28px, 3.4vw, 40px); font-weight: 900; line-height: 1.3; }
.phones { flex: 2 1 520px; display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 20px; }
.phones img { border-radius: 28px; border: 1px solid var(--phone-border); }
@media (max-width: 560px) { .phones { gap: 10px; } .phones img { border-radius: 16px; } }

.two-col { display: grid; grid-template-columns: repeat(auto-fit, minmax(300px, 1fr)); gap: 48px; align-items: start; }
.two-col > div { display: flex; flex-direction: column; gap: 14px; }
.two-col h2 { font-size: 28px; }
.two-col p { margin: 0; color: var(--text-muted); font-size: 15px; }
.two-col code { color: var(--text); }
pre.cmd { margin: 0; background: var(--code-bg); color: var(--code-text); border-radius: 14px; padding: 18px 20px; font-size: 13px; overflow-x: auto; }
pre.cmd .prompt { color: #8E8E89; user-select: none; }

.download { background: var(--accent); color: #111113; border-radius: 28px; padding: 56px 48px; display: flex; flex-wrap: wrap; align-items: center; justify-content: space-between; gap: 32px; }
.download h2 { margin: 0 0 10px; }
.download p { margin: 0; max-width: 640px; font-size: 15px; color: #3A3320; }
.download a.btn { background: #111113; color: #F5C842; font-weight: 700; font-size: 17px; }
@media (max-width: 560px) { .download { padding: 36px 24px; } }

.site-footer { border-top: 1px solid var(--rule); padding: 40px 0 56px; }
.site-footer .wrap { display: flex; flex-wrap: wrap; justify-content: space-between; gap: 24px; font-size: 13px; color: var(--text-faint); }
.site-footer p { margin: 0; max-width: 760px; }